Navigation Links
Arctic coring expedition continues to yield new clues

For the second time in as many months, the IODP Arctic Coring Expedition (ACEX) is making news with new analysis of ocean-floor sediments. In the Aug. 10 issue of Nature, an article by several of the expedition scientists summarizes their findings: more evidence that the Arctic was extremely warm, unusually wet, and ice-free up to the time the last massive amounts of greenhouse gases were released into the Earth's atmosphere ?a period calculated to have occurred 55 million years ago, and known as the Paleocene/Eocene thermal maximum, or PETM.

Researchers have long recognized that a massive release of greenhouse gases, probably carbon dioxide or methane, occurred during the PETM. Surface temperatures also rose in many places by as much as 15 degrees Fahrenheit in the (relative) geological instant of about 100,000 years.

Arctic sediment samples were largely unavailable until 2004, when ACEX scientists recovered the first deep-ocean sediment samples from beneath the ice-laden waters near the North Pole. ACEX, only the second scientific expedition to be conducted by the Integrated Ocean Drilling Program (established 2003), recovered 339 meters of subseafloor sediment samples.

"Building a picture of ancient climatic events is a lot like putting together a jigsaw puzzle, and what ACEX allowed us to do was fill in a blank section of the PETM picture," said Gerald Dickens, a Rice University geochemist and co-author, who conducted the initial, shipboard chemical analyses of all the ACEX core samples.

"The ACEX cores clearly show that the Arctic got very warm and wet during the PETM," Dickens said. "Even tropical marine plants thrived in the balmy conditions."

In today's oceans, certain species of microscopic plants are known to rapidly multiply and create algal blooms. Dickens said that fossils of these plants ?known only to originate in the tropics before the PETM ?are commonly seen in the ACEX cores. Furthermore, th e chemistry of the organic carbon in the ACEX cores may rule out some earlier theories about what caused the PETM. The diminution of these alternate explanations strongly suggests that an enormous amount of carbon entered the atmosphere at the beginning of the PETM, either from volcanic eruptions, or the melting of oceanic gas hydrates ?mixtures of methane and ice on the seafloor.


Source:Integrated Ocean Drilling Program Management International

Related biology news :

1. Grizzlies set to invade high Arctic?
2. Innovative collaboration brings Arctic science into the classroom
3. Census of Marine Life explorers surprised by diversity, density of Arctic creatures
4. Industrial contaminants spread by seabirds in High Arctic, new Canadian study shows
5. Lands surface change on Alaska tundra creating longer, warmer summers in Arctic
6. Displaced songbirds navigate in the high Arctic
7. Scientists to employ Arctic ice and polar bears to protect diversity of worlds crops
8. Arctic expedition will investigate alien-like glacier
9. Record air pollution above the Arctic
10. Pollutant haze heats the Arctic
11. New method confirms importance of fungi in Arctic nitrogen cycle
Post Your Comments:

(Date:5/9/2016)... -- Elevay is currently known as the ... high net worth professionals seeking travel for work   ... there is still no substitute for a face-to-face meeting. ... deal with a firm handshake. This is why wealthy ... citizenship via investment programs like those offered by the ...
(Date:4/28/2016)... India , April 28, 2016 ... Infosys (NYSE: INFY ), and Samsung SDS, a ... that will provide end customers with a more secure, ... services.      (Logo: ) , ... services, but it also plays a fundamental part in enabling ...
(Date:4/26/2016)... BANGALORE, India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a ... ), and Onegini today announced a partnership to ... banking solutions.      (Logo: ... banks to provide their customers enhanced security to ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... Cancer ... what they believe could be a new and helpful biomarker for malignant pleural ... Click here to read it now. , Biomarkers are components in the ...
(Date:6/27/2016)... (PRWEB) , ... June 27, 2016 , ... ... operations for Amgen, will join the faculty of the University of North ... adjunct professor of strategy and entrepreneurship at UNC Kenan-Flagler, with a focus on ...
(Date:6/24/2016)...  Regular discussions on a range of subjects including policies, ... entities said Poloz. Speaking at a lecture to ... he pointed to the country,s inflation target, which is set ... "In certain areas there needs ... economic goals, why not sit down and address strategy together?" ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Researchers at the ... commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are the subject ... it now. , Diagnostic biomarkers are signposts in the blood, lung fluid or ...
Breaking Biology Technology: